1. Field of the Invention
The present invention is directed to: screens for vibratory separators and shale shakers; vibratory screening methods; and separators and shale shakers used in such methods; and, in certain particular aspects, to methods for separating different size particles from the top of a screen assembly on a vibratory separator device.
2. Description of Related Art
Vibratory separators are used in a wide variety of industries to separate materials such as liquids from solids or solids from solids. Typically such separators have a basket or other screen holding or mounting apparatus mounted in or over a receiving receptacle or tank and vibrating apparatus for vibrating the basket. One or more screens is mounted in the basket. Material to be treated is introduced to the screen(s) and separated material on top of the screen(s) flows off an end of an end screen. In many screens used with vibratory separators, there are a plurality of spaced-apart supports that support screening material on the screen.
With certain prior art screen assemblies used in vibratory separators and shale shakers, screening material is mounted on a frame or support and the screening material extends over substantially all of the frame""s or support""s area; but there is an end area that is solid and is a boundary for the screening material. Separated material on the top of the screen that is to exit from the end of the screen moves off of the screening material, over this solid end area, and then off of the screen assembly. In many prior art screen assemblies this end area is relatively smooth compared to the relatively contoured or non-smooth surface presented to fluid by the screening material.
Separated material, e.g., but not limited to, drilling solids, can accumulate at the very end of the screening material and tend to bunch up and agglomerate rather than move off the screen end over the solid end area. Whereas the screening surface of the screening material provides non-smooth areas on which a solid particle can gain a foothold and move forward and non-smooth areas that can launch a solid particle forward, the smooth end area presents only a smooth solid surface that accomplishes no facilitation of particle movement. Particularly when a screen is inclined so that separated material is moving xe2x80x9cuphill,xe2x80x9d this phenomenon of solids accumulation can occur.
As shown in FIGS. 1A and 1B, it is also a known phenomenon in the prior art for separated solids to move down a screen and to tend to move above open screening areas and to tend to move away from areas of screening material beneath which are located support ribs, bars, members, strips, beams, etc. FIG. 1A shows relatively large solids LS moving down and off a screen SC above open screening areas OA. Relatively smaller solids SS move down and off the screen above supports (not shown) under the screen SC. Of course, some solids LS can and do move in the areas in which the smaller solids SS move and vice versa.
To illustrate this phenomenon, a screen SR in FIG. 1B is shown with its screening material removed so that a plurality of support ribs RB are exposed. Larger solids SL tend to move on screening material in areas beneath which no rib is present; and relatively smaller solids SD tend to move in the areas beneath which the ribs RB are located.
In the prior art no effort has been made to take advantage of this particle separation by size that occurs on top of vibratory separator screens. Rather, the combined flow of particles of all sizes flows off the end of a screen and into a single tank, receptacle, or collection container or onto the ground.
FIGS. 2A-2E show a prior art screen assembly 1 with a frame 2, cross supports 3, and screening mesh 4. A plurality of openings 5 extend through the frame 12. Typically the screening mesh 4 is one, two, three or more layers of screening material. The top surfaces of the frame parts are typically smooth.
There has long been a need, recognized by the present inventors, to overcome the deleterious effects of material accumulation and agglomeration at the non-smooth end area of a screen assembly. There has long been a need, recognized by the present inventors, for an efficient and effective method to utilize the particle separation that occurs on the top of screens with lower support members on vibratory separators.
The present invention discloses, in certain aspects, a screen assembly for a vibratory separator or shale shaker with a frame or other screen support with a plurality of openings therethrough, the frame having a material exit end, screening material on the frame over the openings, the frame having an end area at the material exit end of the frame, and end structure or apparatus at the end area for facilitating material movement over the end area and off the screen assembly.
The present invention discloses, in certain aspects, a screen assembly with a frame or other screen support with a plurality of openings therethrough, the frame having a material exit end, screening material on the frame over the openings, wherein set or hardened adhesive material, epoxy or glue connects the screening material to the frame, the screening material having a top surface, portions of the adhesive material at the top surface of the screening material, material or solids movable on the portions of the adhesive material, the portions of the adhesive material having portion apparatus or structure for impeding the movement of solids on the portions and/or for directing material or solids off of the portions.
The present invention discloses, in at least certain aspects, screen assemblies with structure at an end area that is non-smooth and which facilitates movement of separated material, including, but not limited to, drilling solids and/or drilled cuttings, over and off of the end area of the screen assembly, e.g., by providing a xe2x80x9cfootholdxe2x80x9d for the solids or material rather than a smooth area. In one aspect, the structure includes a roughened end area that is made, for example, by using a file or other tool, or a buffer, grinder or sander on the previously-smooth end area to provide a non-smooth area. With such a tool, etc. gouges, recesses, pits, and/or indentations to any desired depth, and in one particular aspect up to {fraction (1/16)} inch deep, may be provided in the end area. Such gouges, etc. may be in a pattern across the end area or they may be random in size, width, extent and depth. In other aspects, non-smooth areas are provided on areas of the screen (in addition to end areas) to impede material or solids flow over these areas and/or to direct material or solids off of these areas.
In other aspects, a piece of non-smooth material, including, but not limited to screening material of coarse, fine or medium mesh; Kevlar (trademark) material; synthetic fabric; natural fabric, including, but not limited to, burlap, canvas, and denim; woven or air laid web material; and/or releasably cooperating fastener material [e.g., but not limited to hook material, loop material, and Velcro (trademark) material], is used to provide a non-smooth top surface that facilitates material movement over the end area, e.g., by providing a xe2x80x9cfootholdxe2x80x9d for solids rather than a smooth surface; or on other areas of the screening material to impede material or solids flow over these areas and/or to direct material or solids off of these areas. The mesh, etc. may be secured to the screen end area (or to other screen areas, e.g., that have an amount of set or hardened material that can act as a non-screening pathway for material or solids and which can deleteriously affect screen performance) with any suitable adhesive, glue, epoxy, screws, plugs, rivets, bolts, and/or other fastener devices or substances.
In certain embodiments, the width of the non-smooth area is substantially similar to that of the screening material. In other aspects, the width of the non-smooth area is wider than that of the screening material. In yet other aspects the width of the non-smooth area increases from the end of the screening material to a point distal therefrom on the solid end.
In certain embodiments, the present invention discloses, in at least certain aspects, a shale shaker (or vibratory separator) with an apparatus which has upright walls or separation members which channel the flow of relatively small particles flowing along a path above support members on top of a screen on the vibratory separator. The relatively small particles flow between the walls and then into a common receptacle. The relatively larger particles that flow on screening areas that are not above supports for the screen flow off the end of the screen and do not flow into the common receptacle into which the relatively smaller particles flow. Alternatively no common receptacle is used and each flow line or flow path has its own collector.
It is, therefore, an object of at least certain preferred embodiments of the present invention to provide:
New, useful, unique, efficient, non-obvious screen assemblies and frames for them for vibratory separators and shale shakers which screen assemblies have a non-smooth end area to facilitate the exit of materials from the top of the screen;
New, useful, unique, efficient, non-obvious screen assemblies and frames for them for vibratory separators and shale shakers which screen assemblies have non-screening pathways thereon and structure on the non-screening pathways to impede the flow of material and/or solids on such pathways and/or to direct material and/or solids off such pathways;
Such screen assemblies in which the non-smooth area is provided by altering the solid end area of a screen assembly, e.g., by grinding etc.;
Such screen assemblies in which the non-smooth area is provided by adding structure to the solid end area of a screen that assists in moving material from the top of the screen and off the screen;
New, useful, unique, efficient, non-obvious screen assemblies and frames for them for vibratory separators and shale shakers with non-smooth areas on top of a screen to impede the movement of solids over such areas.
New, useful, unique, efficient, non-obvious screening methods for vibratory separators and shale shakers and methods for using them that employ such screen assemblies;
New, useful, unique, efficient, non-obvious screening methods for vibratory separators and shale shakers and methods for using them to separate components of material to be treated thereby by size;
New, useful, unique, efficient, non-obvious screening methods for vibratory separators and shale shakers and methods for using them to separate components of material to be treated thereby by size;
Such methods that employ new, useful, unique, efficient, non-obvious apparatuses to remove particles from a shaker or separator and separate them by size; which, in certain particular aspects are area isolating particle reception apparatuses, scoop apparatuses and/or end trough apparatuses; and.
New, useful, unique, efficient, non-obvious shakers and vibratory separators that use such apparatuses.
The present invention recognizes and addresses the previously-mentioned problems and long-felt needs and provides a solution to those problems and a satisfactory meeting of those needs in its various possible embodiments and equivalents thereof. To one of skill in this art who has the benefits of this invention""s realizations, teachings, disclosures, and suggestions, other purposes and advantages will be appreciated from the following description of preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. The detail in these descriptions is not intended to thwart this patent""s object to claim this invention no matter how others may later disguise it by variations in form or additions of further improvements.